Balance in gastrointestinal microbiota is the fundament to a healthy broiler gut. It is a necessity for optimal broiler performance. Different factors like stress, nutrition, farm management, etc. can cause disbalance in the microbiota leading to non-optimal absorption and use of nutrients. This phenomenon called “dysbiosis” can result in higher mortality and lower growth performances.

The gut of broilers face different challenges. Battling major pathogens like Salmonella is an extensive task for all farmers throughout the world, especially in feeds were antibiotic growth promoters are banned. In search of a good way to cope with this task, the application of medium-chain glycerides have proven to be valuable in antibiotic-free feeds. Phytogenic components like oregano oil are promising as well.

An in vitro test confirmed the effect and selectivity of these components towards both Salmonella Paratyphi B var.Java (strain KS 204) and Salmonella Enteriditis (strain MB4472).

The gut of broilers face different challenges. Battling major pathogens like Salmonella is an extensive task for all farmers throughout the world, especially in feeds were antibiotic growth promoters are banned. Photo: Mark Pasveer

Trial methods

Test tubes with liquid medium (pH 5) mixed with different concentrations of the components caproic acid (C6), caprylic acid (C8), lauric acid (C12) and carvacrol were inoculated with Salmonella Java or Salmonella Enteriditis in separate test tubes. After incubation for 20 hours at 41.5°C the tubes were checked for clarity/turbidity. The Minimal Inhibitory Concentration (MIC) of the tested components was determined: lowest concentration at which the tested components have an observable inhibiting effect on growth of tested Salmonella strain (clear, not turbid tubes).

The broth of the test tubes were plated out and incubated for 27 hours at 37°C. The Minimal Bactericidal Concentration (MBC) was defined as lowest concentration at which no growth on the plates is observed.

Fatty acid C6 and C8 showed for both Salmonella strains an MBC and MIC <0,063% whereas the>in vitro test indicated an MBC for lauric acid greater than 1%. The tested concentrations of carvacrol were 10 to 100 times lower, but both MBC and MIC were found to be even lower than the lowest tested concentration :<0,00063%.>

Helping the fight against Salmonella

These results indicate that selected medium-chain glycerides and well-chosen phytogenic components can help the broilers to cope with challenges, like Salmonella. An upgraded slow release concept based on selected medium-chain glycerides (MCG) and well-chosen phytogenic has been validated by Aveve Biochem in practical farms.

Place of action

At a Belgian farm, one stable of 32,760 broilers received a standard feed without the supplement (NC), the 28,700 birds of a second stable were fed the standard feed supplemented with a firm dose of the upgraded medium-chain glycerides (NC+AveMix PLUS). The occupancy of the stables were the same: same number of birds per square meter. Growth rate, feed intake and mortality were recorded for the 2 stables and the corresponding Feed Conversion Ratio (FCR) were calculated and compared.

Highly challenged birds

During this practical trial the weather conditions were not at all optimal, a lot of very hot days passed by, which challenged the birds of both stables. The broilers fed with the supplemented feed were coping better with this challenge: 29% lower mortality was registered at the end of the trial, 38 days later. (NC : 4,15% vs. PLUS: 2,96%).

This was not at all at the expense of the growth parameters: similar growth rate (NC : 55,78% vs. PLUS :56,21 g/d) and 3,2% better FCR (NC : 1,738 vs. PLUS : 1,683) was recorded for the supplemented feed compared to the NC.

The MCG upgraded with specific aromatic compounds did prevent major outbreaks, moreover it positively influenced gut microbiota balance resulting in less bird deaths and improved technical performances of the birds in antimicrobial free-feeds.

Balanced gut flora

The combined-supplement has been re-validated in similar practical trials at a lower dosage reconfirming lower mortality rate (-15% and -18%) and better growth performance (FCR : -1,8% and -2,6% ; growth rate : +3,5% and +0%). The use of this well-selected combination can be regarded as an aid for the birds to keep the gut flora more in balance and cope better with challenges.